|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1992 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1991 : ¥1,700,000 (Direct Cost : ¥1,700,000)
|Keywords||Positron Annihilation / Positron Lifetime / 2,3-dichloro-9,10-anthraquinone / MnPS_3 / Fullerene / Carbon seventy / Tetrathiafulvalene / Graphite Intercalation Compound / 陽電子-電子対消滅 / 陽電子寿命 / 2,3-ジクロロ-9.10-アントラキノン / マンガンリンカルコゲナイド / フラーレン / C_<70> / テトラチアフレバレン / 黒鉛層間化合物 / 2,3-ジクロロ-9,10-アントラキノン / テトラチアフルバレン / 陽電子ー電子対消滅 / ヘキサメチルベンゼン / ヘキサクロロベンゼン / πー電子の運動量分布 / ポジトロニウム|
1. Synthesized 2,3-dichloro-9,10-anthraquinone, highly purified by zone-melting, was grown by the Bridgman method to a single crystal in which the molecular planes were oriented nearly in parallel. Positrons injected into a crystal, 14 x 8 x 6 mm^3 in size, which contained ca. 7.4 x 10^5 Bq^<22>NaCl at the center, emitted 511 keV gammaray upon annihilation with electrons in the crystal. Positrons were found to decay with a single lifetime component of 310 ps and the Doppler-broadening width along gamma// a was narrower than that along gamma// b or c, which demonstrated that the region where electrons moved freely was wider along the molecular C_<2v> axis. 2. The electronic structures of tetrathiafulvalene and pyridine intercalated into MnPS_3 single crystals were studied : the former was found to be in the mixed-valence state between TTF^+ and TTF^0, and the latter to form hydrogen-bonded PyH^+-Py complexes solvated with neutral pyridine molecules. The pyridine species were oriented perpendicularly to P_2S_6^<4-> layers. 3. A ternary intercalation compound of CsC_8 with hydrogen could be prepared by the reaction between CsC_8 and active hydrogen atoms generated on a hot tungsten filament. Gettering rates of RbC_8, KC_8 and CsC_8 for hydrogen gas were found to be large in this sequence, while those for oxygen were all in the order of 10^<-1>s^<-1>. A graphite-bromine intercalation compound in a diamond anvil cell showed pressure-induced phase transitions at 0.3, 0.8 and 1.2 GPa, which were found to be accompanied with inclination-changes of bromine-bonding axis against graphite layers. 4. Vaccum-sublimed C_<60> and C_<70>, isolated by column chromatography with 5% benzene in hexane on alumina, gave the positron-electron annihilation lifetimes of 427 and 403 ps, respectively, while C_<60>I_<0.08> gave two components for the lifetime spectrum.